This invention relates to disposable diapers. More particularly, this invention relates to disposable diapers adapted to be secured in place by adhesive tabs.
Disposable diapers provide substantial advantages in convenience over diapers intended to be laundered and reused, particularly when they are used away from home. In recent years, many different disposable diapers have been proposed and some have been successful in the marketplace. Typical disposable diaper structures comprise a moisture-retaining layer of high liquid-holding capacity and a moisture-impervious backing sheet therefor, generally made of a plastic film such as polyethylene film or the like. Typical disposable diaper structures are shown in U.S. Pat. No. 3,612,055 to Mesek et al. and in U.S. Pat. No. Re26,151 to Duncan et al.
As may be seen from the above-cited patents, it is desirable to obviate the problems that are inherent in closure systems which utilize extraneous fasteners such as safety pins, snaps and zippers. To this end, adhesive closure systems have presented acceptable solutions.
In order to protect the adhesive surfaces of the tape tabs, usually a cover strip having a release surface is applied over these adhesive surfaces for subsequent removal when the diaper is about to be used. However, such tabs usually project beyond the confines of the diaper to a considerable extent and interfere with the efficient manufacture and packaging of the diaper. Many prior art cover strips have the further disadvantage that the consumer must dispose of the cover strips when they are separated from the adhesive tabs. This is an inconvenience to the consumer who is positioning the diaper on an infant at the same time.
In an attempt to solve the foregoing problems, U.S. Pat. No. 3,646,937 to Gellert teaches a fastening tab which is provided with a release surface permanently bonded primarily to the inside surface of the diaper. One of the drawbacks of the Gellert arrangement is that the release surface is on the inside of the diaper where it can possibly come in contact with an infant's tender skin.
U.S. Pat. No. 3,921,638 to Schaar teaches a fastening tab which is folded over onto a release surface which is permanently bonded to the diaper. The release surface is transversely aligned with the tabs, and both longitudinal margins of the diaper are folded over in their entirety to cover the adhesive on the fastening tabs. In some of the embodiments, the release surface is on the front surface of the diaper, where it can possibly contact the infant's tender skin.
Commonly assigned U.S. patent application Ser. No. 539,554 by Tritsch, filed Jan. 8, 1975, discloses a structure wherein a release region is provided on the diaper outside surface. A relatively long adhesive tab is attached to the diaper outside surface, and the fixed end of the tab has a release coating to which the free end of the tab is releasably adhered.